def else_test():
    s = input("请输入除数：")
    res = 20 / int(s)
    print("result:", res)


def right_main():
    try:
        print("try code is true")
    except:
        print("right_main error")
    else:
        else_test()

def wrong_main():
    try:
        print("try code is true")
        else_test()
    except:
        print("wrong_main error")

# wrong_main()
right_main()